An international team of researchers from the United States, Germany, and China reports that human-made aerosol emissions into the atmosphere can slow the Atlantic Meridional Overturning Circulation, a vast network of ocean currents linked to the Gulf Stream. The findings appear in Nature Communications, signaling possible effects on climate and regional weather patterns across North America and beyond.
The AMOC moves warm water toward higher latitudes and returns cooler water southward while distributing nutrients across the Atlantic. This circulation helps sustain a milder climate in regions along its route and influences rainfall and energy balance across neighboring continents, shaping daily weather and long-term climate trends for communities in Canada, the United States, and parts of Europe.
Model calculations indicate that rising levels of greenhouse gases together with aerosol emissions from Asia contribute to a slower AMOC. Aerosols originate from vehicle exhaust, coal combustion byproducts, and industrial activity, and they alter atmospheric properties and oceanic heat exchange processes, influencing how heat is stored and transported in the ocean system.
Researchers note that reducing anthropogenic aerosol emissions in Asia could produce twofold benefits: cleaner air locally and a stabilizing effect on the AMOC, potentially moderating regional climate impacts tied to the current system. The work suggests that air quality improvements may coincide with shifts in ocean circulation, underscoring the interconnectedness of atmospheric pollution and ocean dynamics for North American climate resilience.
Earlier research has explored various forces shaping deep ocean flows, including gravitational interactions within the planet’s seas. The new analysis highlights how surface pollutants can propagate through atmospheric and oceanic pathways to influence both deep and surface currents in ways that underscore the complexity of air-sea interactions. This line of inquiry continues to evolve as scientists integrate measurements from satellites, atmospheric sensors, and ocean observation networks to refine projections of AMOC behavior in a changing climate, with particular relevance to climate outlooks for Canadian and American regions.